A photolithography process is often used for forming patterns on a substrate such as that used in making a liquid crystal display panel. The substrate is commonly a glass substrate, and the photolithography process generally includes a coating process, an exposing process, and a developing process. The coating process involves coating a photoresist layer on the substrate. The exposing process involves exposing the photoresist layer through a photo mask, so that patterns of the photo mask are correspondingly transferred to the photoresist layer. The developing process involves removing unwanted portions of the photoresist layer by using a developing solution, in order to obtain a patterned photoresist layer.
When the developing process is used in fabricating a thin film transistor liquid crystal display (TFT LCD), the developing solution generally is formed on the photoresist layer by relative movement between the substrate and a developing solution dispensing nozzle. After reaction of the developing solution with the unwanted portions of the photoresist layer is finished, residual developing solution is removed.
Referring to FIG. 3, this represents a conventional apparatus 1 for removing residual developing solution (not shown) from a substrate 11. The apparatus 1 includes a working table 15, and a supporting frame 14 mounted on the working table 15. The working table 15 includes a plurality of pins 12 extending up from a right top face thereof. The pins 12 can be lowered or retracted into the working table 15, and similarly can be extended back out from the working table 15. A top end of the supporting frame 14 has a dispensing nozzle 13, for dispensing developing solution onto the substrate 11 having a photoresist layer thereon. When the dispensing nozzle 13 dispenses developing solution, the pins 12 are in a lowered position or are fully retracted inside the working table 15. After reaction of the developing solution with unwanted portions of the photoresist layer is finished, the pins 12 are extended back up or out from the working table 15, thereby lifting up a right end of the substrate 11. Because the substrate 11 is inclined, residual developing solution flows off from the substrate 11 by force of gravity. Thus, the residual developing solution is removed.
However, when the substrate 11 is lifted, it is liable to be bent or even crack. In addition, the next stage in processing the substrate 11 only can be executed after the residual developing solution has flowed down from the right end thereof and off from the left end thereof. This may take an unduly long time.
Referring to FIG. 4, this represents another conventional apparatus 2 for removing residual developing solution (not shown) from a substrate 21. The apparatus 2 includes a working table 25, and a supporting frame 24 mounted on the working table 25. The working table 25 includes a low-profile, rectangular plate 22 extending up from a middle of a top face thereof. The plate 22 can be lowered or retracted into the working table 25, and similarly can be extended back out from the working table 25. A top end of the supporting frame 24 has a dispensing nozzle 23 for dispensing developing solution onto the substrate 21. When the dispensing nozzle 23 dispenses developing solution, the plate 22 is in a lowered position or is fully retracted inside the working table 25. After the reaction of the developing solution with unwanted portions of the photoresist layer is finished, the plate 22 is extended back up or out from the working table 25, thereby lifting a middle portion of the substrate 21. Because the two ends of the substrate 21 are inclined, residual developing solution flows off from the substrate 21 by force of gravity.
Because the two ends of the substrate 21 are inclined, the time needed for the developing solution to flow down and off from the substrate 21 is shorter than that needed when using the apparatus 1. However, the substrate 21 is still liable to be cracked or damaged.
What is needed, therefore, is an apparatus for removing developing solution which does not risk damage to the substrate and which provides quick processing.